Investigation on the Electron Emission Regularity of Sputtered Boron Nitride Thin Films and Microstructured Array Surfaces
Boron nitride (BN) ceramic is an important support material in aerospace, arc discharge devices, and vacuum electronics. The electron emission properties of BN surfaces are of significance among various space applications. In this work, by preparing BN thin films and microstructured BN bulks, we hav...
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| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-03-01
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| Series: | Inorganics |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2304-6740/13/4/102 |
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| Summary: | Boron nitride (BN) ceramic is an important support material in aerospace, arc discharge devices, and vacuum electronics. The electron emission properties of BN surfaces are of significance among various space applications. In this work, by preparing BN thin films and microstructured BN bulks, we have investigated the influence of the surface physical properties on the electron emission coefficient (EEC). The results showed that the surfaces of BN films, which were prepared by magnetron sputtering, produced serious gas adsorption and organic contamination when they were left for 10 days, and these surface modifications made the EEC of BN film surface decrease to a certain extent. The argon ion cleaning experiments indicated that the process of ion cleaning was able to partly eliminate the surface adsorption and contamination for the BN film. The EEC of the cleaned BN film surface was significantly improved compared to that of the original polluted BN film surface, with an EEC peak value of about 3.2 instead of 3.0 for the original polluted surfaces. By contrast, the EEC curves of the BN bulk show some difference, with the peak values of the EEC curves being 2.62 for the untreated BN bulk. The results of laser etching on the BN bulk surface to form microarray structures show that the EEC of BN bulk decreases significantly with the increase of the average aspect ratio of the microstructures. The EEC peak values of the BN bulks decrease from 2.62 to 1.16 when the porosity of the BN bulk reaches 49.11% and the aspect ratio reaches 1.36, indicating that constructing a surface microstructure is an effective method to achieve EEC reduction. By employing the electron trajectory tracking algorithm and the phenomenological model of electron emission, the effect of microstructure on EEC for BN bulk was quantitatively explained. The results of the study are of engineering application significance for vacuum devices involving the electron emission process of BN ceramic. |
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| ISSN: | 2304-6740 |